1. Field of the Invention
This invention relates to an improved anchoring and insulation arrangement for use in conjunction with building structures having a masonry construction veneer anchored to steel stud framing or a masonry backup wall. More particularly, the invention relates to a channel anchoring system that secures both the veneer and the insulation to the framing or backup wall without compromising the insulation. The invention is applicable to seismic-resistant structures and to structures requiring insulation.
2. Description of the Prior Art
The move toward more energy-efficient insulated veneer wall structures has led to the need to create a highly-insulated building envelope, which separates the interior environment and the exterior environment of a cavity wall structure. The building envelope is designed to control temperature changes, while maintaining structural integrity. Thermal insulation is used within the building envelope to maintain temperature and therefore restrict the formation of condensation within the cavity. High R-value thermal insulation that is secured to the backup wall or framing is essential to maintaining an energy-efficient building structure. The present invention provides a non-invasive compartment for insulation installation, while simultaneously providing a fast track anchoring channel to interconnect with a veneer tie for embedment in the mortar joints of the masonry veneer.
The present anchoring system provides a secure insulation compartment for rigid, batt, board, spray-on and, in particular, Roxul® insulation. Roxul® insulation is a common choice of insulation in commercial construction. Roxul® is a rock-based mineral fiber insulation comprised of basalt rock and recycled slag which are melted together and spun into fibers and complies with the greater insulation requirements imposed by government standards. It is commonly referred to as stone wool. Roxul® products are corrosion resistant, moisture and mold resistant, fire resistant, energy efficient, and minimize thermal bridging. The structural nature of the Roxul® insulation combined with the anchor insulation compartment of this invention, provide a secure insulation attachment to the backup wall or framing.
In the past, anchoring systems have taken a variety of configurations. Where the applications included masonry backup walls, wall anchors were commonly incorporated into ladder—or truss-type reinforcements and provided wire-to-wire connections with box-ties or pintle-receiving designs on the veneer side. In the late 1980's, surface-mounted wall anchors were developed by Hohmann & Barnard, Inc., now a MiTek-Berkshire Hathaway Company, and patented under U.S. Pat. No. 4,598,518. The invention was commercialized under trademarks DW-10®, DW-10-X®, and DW-10-HS®. These widely accepted building specialty products were designed primarily for dry-wall construction, but were also used with masonry backup walls. For seismic applications, it was common practice to use these wall anchors as part of the DW-10® Seismiclip® interlock system which added a Byna-Tie® wire formative, a Seismiclip® snap-in device—described in U.S. Pat. No. 4,875,319 ('319), and a continuous wire reinforcement.
In an insulated dry wall application, the surface-mounted wall anchor of the above-described system has pronged legs that pierce the insulation and the wallboard and rest against the metal stud to provide mechanical stability in a four-point landing arrangement. The vertical slot of the wall anchor enables the mason to have the wire tie adjustably positioned along a pathway of up to 3.625-inch (max.). The interlock system served well and received high scores in testing and engineering evaluations which examined effects of various forces, particularly lateral forces, upon brick veneer masonry construction. However, under certain conditions, the system did not sufficiently maintain the integrity of the insulation. Also, upon the promulgation of more rigorous specifications by which tension and compression characteristics were raised, a different structure—such as one of those described in detail below—became necessary.
The engineering evaluations further described the advantages of having a continuous wire embedded in the mortar joint of anchored veneer wythes. The seismic aspects of these investigations were reported in the inventor's '319 patent. Besides earthquake protection, the failure of several high-rise buildings to withstand wind and other lateral forces resulted in the incorporation of a continuous wire reinforcement requirement in the Uniform Building Code provisions. The use of a continuous wire in masonry veneer walls has also been found to provide protection against problems arising from thermal expansion and contraction and to improve the uniformity of the distribution of lateral forces in the structure.
Shortly after the introduction of the pronged wall anchor, a seismic veneer anchor, which incorporated an L-shaped backplate, was introduced. This was formed from either 12- or 14-gauge sheetmetal and provided horizontally disposed openings in the arms thereof for pintle legs of the veneer anchor. In general, the pintle-receiving sheetmetal version of the Seismiclip interlock system served well, but in addition to the insulation integrity problem, installations were hampered by mortar buildup interfering with pintle leg insertion.
There have been significant shifts in public sector building specifications, such as the Energy Code Requirement, Boston, Mass. (see Chapter 13 of 780 CMR, Seventh Edition). This Code sets forth insulation R-values well in excess of prior editions and evokes an engineering response opting for thicker insulation and correspondingly larger cavities. Here, the emphasis is upon creating a building envelope that is designed and constructed with a continuous air barrier to control air leakage into or out of conditioned space adjacent the inner wythe, which have resulted in architects and architectural engineers requiring larger and larger cavities in the exterior cavity walls of public buildings. These requirements are imposed without corresponding decreases in wind shear and seismic resistance levels or increases in mortar bed joint height. Thus, wall anchors are needed to occupy the same ⅜-inch high space in the inner wythe and tie down a veneer facing material of an outer wythe at a span of two or more times that which had previously been experienced.
As insulation became thicker, the tearing of insulation during installation of the pronged DW-10X® wall anchor, see infra, became more prevalent. This occurred as the installer would fully insert one side of the wall anchor before seating the other side. The tearing would occur at two times, namely, during the arcuate path of the insertion of the second leg and separately upon installation of the attaching hardware. The gapping caused in the insulation permitted air and moisture to infiltrate through the insulation along the pathway formed by the tear. While the gapping was largely resolved by placing a self-sealing, dual-barrier polymeric membrane at the site of the legs and the mounting hardware, with increasing thickness in insulation, this patchwork became less desirable.
As concerns for insulation integrity grow, the ability to install high R-value thermal insulation, without breaching the insulation with a fastener or anchor, becomes an essential part of the construction process. The present invention provides a response by offering a pocket component formed by the anchors for insulation, which secures the insulation to the backup wall or framing without piercing the insulation or degrading the insulative properties.
In the course of preparing this Application, several patents, became known to the inventors hereof and are acknowledged hereby:
Pat. No.InventorIssue Date4,703,604MullerNov. 3, 19874,869,038CataniSep. 26, 19895,063,722HohmannNov. 12, 19915,671,578HohmannSep. 20, 19977,059,577BurgettJun. 13, 20067,481,032TarrJan. 27, 20097,562,506Hohmann, Jr.Jul. 21, 20098,122,663Hohmann, Jr., et al.Feb. 28, 20128,215,083Toas et al.Jul. 10, 2012
U.S. Pat. No. 4,703,604—Muller—Issued Nov. 3, 1987 Discloses a method of building a structure formed from a masonry wall with an outer face carrying frame members, insulation and sheathing. The insulation is fitted between the frame members and against the brace panel with the anchors fixed to the insulation and framework with the stems of the anchor projecting away from the panel and past the insulation.
U.S. Pat. No. 4,869,038—Catani—Issued Sep. 26, 1989 Discloses a veneer wall anchoring system that interconnects a backup wall of block construction with a brick veneer wall. A wall of rigid insulation is placed against an outer face of the backup wall with the plates extending through the insulation. The plate includes a spring clip fastener which engages the insulation wall.
U.S. Pat. No. 5,063,722—Hohmann—Issued Nov. 12, 1991 Discloses a gripstay channel veneer anchor assembly that engages an insulation layer and the inner wythe. A clip securement projects through the channel, pierces the insulation and engages the support member.
U.S. Pat. No. 5,671,578—Hohmann—Issued Sep. 30, 1997 Discloses a surface-mounted seismic construction system. The system includes a wire formative anchor and box tie. The anchor includes a seismic clip and reinforcement wire and the anchor eye portions are oriented to secure the insulation panels which are protected by insulation shields
U.S. Pat. No. 7,059,577—Burnett—Issued Jun. 13, 2006 Discloses an insulated concrete wall system. The system includes insulation panels which are secured by t-shaped wall studs. The wall studs are anchored within the concrete.
U.S. Pat. No. 7,481,032—Tarr—Issued Jan. 27, 2009 Discloses a stud system for supporting spray insulation to a concrete structure. The stud includes a laterally extending web to promote adherence of the insulation.
U.S. Pat. No. 7,562,506—Hohmann, Jr.—Issued Jul. 21, 2009 Discloses a notched, surface-mounted wall anchor and anchoring system. The folded sheetmetal anchor includes a notch that, upon surface-mounting, form small wells in the portion of the notch extending into the insulation to entrain water vapor, condensate and water to prevent entry into the wallboard.
U.S. Pat. No. 8,122,663—Hohmann, Jr. et al.—Issued Feb. 28, 2012 Discloses an anchor and reinforcement device for a cavity wall. The device interlocks with a veneer anchor and veneer reinforcements. The system is composed of wire formatives. The wall anchor and reinforcement devices are compressively reduced in height to span insulation mounted on the exterior of the backup wall.
U.S. Pat. No. 8,215,083—Toas et al. —Issued Jul. 10, 2012 Discloses a unitary building exterior envelope product that includes a mineral fiber insulation board. The product is mounted to exterior wall framing members.
None of the prior art listed above provide a channel anchoring system that secures both the veneer and the insulation to the framing or backup wall without impacting the insulation and its insulative properties. As will become clear in reviewing the disclosure which follows, the cavity wall structures benefit from the recent developments described herein that lead to solving the problems of maintaining thermal insulation within the cavity wall. The wall anchor assembly provides a novel pocket compartment for securing the insulation without the use of fasteners that perforate the insulation. The prior art does not provide the present novel cavity wall construction system as described herein below.